# Copyright (c) 2016 The Johns Hopkins University/Applied Physics Laboratory
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

from abc import ABCMeta
from abc import abstractmethod

import six


@six.add_metaclass(ABCMeta)
class CryptographicEngine(object):
    """
    The abstract base class of the cryptographic engine hierarchy.

    A cryptographic engine is responsible for generating all cryptographic
    objects and conducting all cryptographic operations for a KMIP server
    instance.
    """

    @abstractmethod
    def create_symmetric_key(self, algorithm, length):
        """
        Create a symmetric key.

        Args:
            algorithm(CryptographicAlgorithm): An enumeration specifying the
                algorithm for which the created key will be compliant.
            length(int): The length of the key to be created. This value must
                be compliant with the constraints of the provided algorithm.

        Returns:
            dict: A dictionary containing the key data, with the following
                key/value fields:
                * value - the bytes of the key
                * format - a KeyFormatType enumeration for the bytes format
        """

    @abstractmethod
    def create_asymmetric_key_pair(self, algorithm, length):
        """
        Create an asymmetric key pair.

        Args:
            algorithm(CryptographicAlgorithm): An enumeration specifying the
                algorithm for which the created keys will be compliant.
            length(int): The length of the keys to be created. This value must
                be compliant with the constraints of the provided algorithm.

        Returns:
            dict: A dictionary containing the public key data, with the
                following key/value fields:
                * value - the bytes of the key
                * format - a KeyFormatType enumeration for the bytes format
            dict: A dictionary containing the private key data, identical in
                structure to the public key dictionary.
        """